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Zman Member Posts: 7,441
I've been thinking lately about the way we treat the condensate from condensing boilers and furnaces.

First off, It appears that propane condensate is more prone to damaging copper and cast piping than natural gas. There is nothing scientific about the observation, Ive just never seen the damage on natural gas systems that I have seen with propane.

I am thinking that the condensate neutralizers that everyone sells probably work pretty well as long as the media is changed regularly. It doesn't seem like like most systems get changed ever.

My question is,has anyone tested the PH before and after neutralizing?

Has anyone tested an unmaintained neutralizer?

Is my observation about Propane and Natural gas true or my imagination?

How bad is it to put untreated condensate in cast pipes?

It seems this is one of those things everyone does without much consideration, or maybe it is just me.

"If you can't explain it simply, you don't understand it well enough"
Albert Einstein


  • TonyS
    TonyS Member Posts: 849
    Condensate PH

    The acid in condensate is from co2. If you let it sit it will remove itself just like a can of soda goes flat so does condensate, the warmer the faster. This is why a well with acid water will always eat out the cold copper, the water heater will usually cook the co2 out . I have a Navien tankless in my house that I still haven't hooked up to a pump. So I always have a five gallon bucket of condensate to test. I have a solar prefeed so it hasn't really been a big hassle. LOL

    Because the code requires a neutralizer I will usually tie in a tub drum trap with the plug up and a 2 foot standpipe and fill it 1/2 way with calcite.They hold enough calcite for several years and work fine.

    Some jobs I have to dump outside, I remove the duckbill check from my condensate pipe and use it as a drain back system, it works well just don't dump it on a sidewalk.

    I believe it is going to be a short time till the sewer administration realizes there are millions of gallons of unmetered condensate going down the sewer. Being the money hungry fools they are and to pay for pensions for people who haven't worked in 40 years, they will find a way to tax condensing furnaces and boilers. Then getting rid of condensate onsite will make alot more sense.
  • Zman
    Zman Member Posts: 7,441
    Make sense

    Propane combustion generally has higher CO2 than natural gas.


    Are you saying it will off gas to the air?


    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • TonyS
    TonyS Member Posts: 849

    it will.
  • Zman
    Zman Member Posts: 7,441
    Anyone else?

    Thank you Tony.

    Does anyone else want to weigh in?

    I was kind of hoping someone had tested the PH before and after or maybe had a rotten pipe horror story to tell.

    If my post was about delta t  vs delta p or open vs closed heating I would have had 50 passionate responses by now.

    This seems like one of those subjects that we all just bury our heads in the sand and install and forget a neutralizer.

    Does it work? How long does it last? Is the PH really any worse than dumping a few gallons of orange juice down the toilet? How about NG vs LPG?

    How about this. Chevy Trucks are the best! No one should own a Ford, Dodge or Toyota.

    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Vinny_5
    Vinny_5 Member Posts: 59
    Hi Carl

    I actually did test it before and after and posted the results here:


    Hope it helps.

This discussion has been closed.